In the pre-title opening moments of First Descent, a helicopter drops five snowboarders on the scrawny tip of what looks like a 7,600-foot-tall shark tooth. They huddle together miserably against the winds, and in a few moments, they're supposed to dive off the edge of their untrammeled Alaskan mountain and steer their boards down a slope that tilts an insane 60 degrees. This is an excellent windup, and it's not just for some middling ''Do the Dew'' TV spot, either though this sometimes thrilling extreme-sports doc was produced by an unlikely new brand-extending outfit called Mountain Dew Films. (Hey, as far as offshoots go, this movie goes down a lot easier than Code Red.)
As for that scary peak, you must wait till the end to see who actually slides off it. After the opening cliff-hanger, the movie pulls back to tell two interweaving stories. One follows that group of telegenic freestyle pros as they shear across rocky gorges, fly like cannonballs, and (in one big money shot) outrun an avalanche in Alaskan backcountry. The other delivers the history of American snowboarding, which used to be so outlaw that some snobby skiers feared that snowboarders carried guns. Snowboarding is a bigger deal in other countries, and watching weird footage from an arena snow-stunt show in Tokyo, you might come to a new appreciation for the way-flashy sport. In that Tokyo show, the scale is so gargantuan complete with monster jumps, ecstatic fans, pyrotechnic showers, laser lighting, and, best of all, a gong that snowboarding at its most over-the-top, fantastic, and impossible starts to look like science fiction.
First Descent is not as eloquent, and thus not as electrifying, as Stacy Peralta's Dogtown and Z-Boys or Riding Giants, the two jock docs it's clearly modeled after. No matter: Visually, MD Films offers up a sugar rush.